We drive each one of these monitors with a separate 20 watt Ultra Linear Push Pull 6L6 amplifier.

Sonic impressions are acceptable, maybe a little lacking in high frequency detail. The Sennheiser HD-600 headphones are used for listening 95% of the time, but when we want to jam to music or rumble the walls with some voodoo audio, the Monitors sure perform! For the money they work great. Read the reviews on the site, lots of different views there.